Up and down the country, thousands of children are honing their skills with eggs, spoons and sacks. It can only mean one thing: sports day is nigh. Brace yourself for dropped batons, three-legged runners, chubby weeping eight-year-olds . . . and overcompetitive parents.

According to a survey by AposTherapy, it's the last group we should be most concerned about. A remarkable 50% of physiotherapists say they've treated sports-day injuries suffered not by kids, but by mums and dads who exerted themselves too much in the parents' race. As a public service aimed at reducing this seasonal surge in demand for scarce NHS resources, we offer a 10-point plan for avoiding embarrassment or, worse, a fractured metatarsal:

• Wear trainers. "I tore my hamstring at my daughter's sports day," says David Castle, who as editor of Running Fitness really should know better, "and it was probably because I was running barefoot." Trying to do the 100m dash in a pair of Manolo Blahniks is equally likely to end in tears.

• Take a chair with you. "Just a foldaway camping chair will do," says Duncan Mason, physio to the UK athletics team. "You'll need it to stretch without arousing the suspicion of other parents."

• While in the chair, stretch your hamstrings: most injuries are caused by parents not warming their leg muscles up properly. "Keep your back upright and extend one leg at a time, straightening them until you feel the stretch," advises Mason.

• If you're really serious about the warm-up, find a wall (well away from your fellow parents' prying eyes). "You'll need a wall to stretch your calves," warns Paul Gough, a former physio for Middlesbrough FC. "Put your hands against the wall, put one leg behind the other – with the heel flat on the ground – and hold."

• Never run three-legged unless it's with someone of the same height. "Then you're less likely to fall over," notes Castle sagely.

• Avoid the sack race at all costs. You'll just look ridiculous.

• Don't take it too seriously. "It's a tortoise-and-hare scenario," says Castle. "If you just aim to finish, you might find you come first anyway because everyone else has fallen over."

• Have a careful look at the competition before the race. If all the other runners are young, fit and wearing new trainers, offer to hold the finishing tape instead.

• Take something to drink – preferably non-alcoholic.

• Skip sports day altogether. Your child will probably be mortified and the parents sporting brand-new trainers will be suspicious, but it might save you a trip to casualty. There's always next year – and now you know the risks, you can start preparing properly.